AmjJa0nu:-x?7h7arm'}  Cinchona  Febrifuge.  29 
were  already  at  hand.  The  dry  bark  is  crushed  into  small  pieces,  but 
not  powdered,  and  is  put  into  wooden  casks,  where  it  is  macerated  in 
the  cold  with  very  dilute  hydrochloric  acid.  The  liquor  is  then  run 
off  into  wooden  vessels,  and  mixed  with  an  excess  of  a  strong  solution 
of  caustic  soda.  A  precipitate  forms,  which  is  collected  on  calico  fil- 
ters, and  well  washed  with  water.  The  precipitate  is  then  dried  at  a 
gentle  heat,  and  powdered.  It  constitutes  the  crude  febrifuge,  which 
is  next  submitted  to  a  process  of  purification.  In  the  latter  process  a 
certain  weight  of  the  crude  product  is  dissolved  in  dilute  sulphuric 
acid,  and  a  small  quantity  of  a  solution  of  sulphur  in  caustic  soda  is 
added  to  the  liquor.  After  the  lapse  of  twenty-four  hours  the  liquor 
is  carefully  filtered.  The  filtrate  is  mixed  with  caustic  soda,  and  the 
resulting  precipitate  collected  on  calico,  washed  with  a  small  quantity 
of  water,  dried  and  powdered.  It  is  then  ready  for  issue,  and  is  sent 
out  under  the  name  of  "  Cinchona  Febrifuge."  A  position  for  the 
factory  sheds  was  chosen  conveniently  near  the  dry  bark  go-downs> 
and  so  situated  on  the  side  of  the  hill  that  a  copious  supply  of  water 
could  be  obtained  at  a  level  with  the  roof  of  the  sheds  in  which  the 
maceration  is  conducted.  These  sheds  are  rough,  temporary  erections, 
constructed  with  saplings  and  a  mat  or  thatch  roof.  Down  the  cen- 
tre an  open  drain  is  cut  to  carry  off"  the  waste  liquor.  Over  this  drain 
some  wooden  stands  are  placed,  on  which  the  calico  filters  rest.  The 
filters  are  formed  by  tying  a  square  piece  of  calico  to  a  wooden  frame 
by  the  four  corners.  On  each  side  of  the  shed  is  placed  a  row  of 
twenty-one  casks,  standing  on  end  upon  a  stand  which  elevates  them 
about  two  feet  from  the  ground.  They  are  empty  beer  barrels,  which 
have  been  purchased  from  the  Commissariat  Department  at  Darjeeline^ 
the  head  removed,  and  the  cask  thoroughly  cleansed.  A  hole  is  cut  in 
the  side  of  the  cask  at  a  level  with  the  bottom,  and  closed  with  a  cork. 
In  front  of  the  casks  a  row  of  tubs,  formed  by  cutting  beer  barrels  in 
halves,  is  placed,  so  that  on  uncorking  the  barrels  the  liquor  will  run 
out  into  .the  tubs.  Outside  the  shed,  at  one  end,  are  a  couple  of  large 
wooden  vats,  at  such  an  elevation  that  liquid  can  flow  from  them  along 
a  bamboo  trough  into  any  one  of  the  barrels  in  the  shed.  The  capa- 
city of  the  vats,  up  to  a  mark  on  the  inside  near  the  top,  is  accurately 
determined.  Water  is  run  into  the  vat  up  to  the  mark,  and  a  certain 
quantity  of  muriatic  acid  is  added,  and  the  whole  well  mixed.  This 
diluted  acid  can  then  be  run  into  any  one  of  the  casks  in  a  line  with 
